Generally, in vehicle compartments, there are employed locking structures for lockingly attaching desired objects to wall portions of various components of the vehicle. Such locking structures are disclosed, for example, in Japanese Patent Application Laid-Open Publication No. 2004-196083 (JP 2004-196083 A). According to the disclosure of JP 2004-196083, a plurality of locking structures are provided on a console device disposed between a driver set and a front passenger seat, and a center cap is mounted, via the locking structures, in a working opening section formed in the console device, to close the working opening section. As the center cap is placed on mounting seating surface portions, formed on peripheral edges of the working opening section, with claw portions of the center cap fitted in the seating surface portions so that small-width flat surface portions, provided on opposed edges of a brake-lever mounting opening portion communicating with the working opening section, are held between claw-shaped portions and projections of the center cap, flanges of the center cap, located over the projections, climb onto the small-width flat surface portions so that the flanges ultimately lie flush with the upper end of the brake-lever mounting opening portion.
However, in order to attach another member (i.e., another desired object) after the locking attachment of the center cap to the console device disclosed in JP 2004-196083 A, there would arise a need to provide, in addition to the locking structures for the center cap, locking support structures on the peripheral edges of the opening section of the console device or mounting structures on the center cap. In the former case, a storage space defined by the center cap and the console device body would be considerably reduced due to the provision of the additional locking support structures, while, in the latter case, design freedom would be considerably limited because some measure for increasing the mechanical strength of the center cap is required. Therefore, there has been a demand for an improved locking structure which can reliably lockingly attach another member or object, such as an accessory, on the console device of the vehicle without adversely influencing the other member or object and without reducing the storage space defined by the center cap and the console device body.